Added "block_or_inline_children" type; added content model for blockquote.
Added "block_or_inline_children" type; added content model for blockquote.

macmillanpublishers/HTMLBook,gitenberg-dev/HTMLBook,oreillymedia/HTMLBook,mushroomgithub/HTMLBook,macmillanpublishers/HTMLBook,gitenberg-dev/HTMLBook,mushroomgithub/HTMLBook,oreillymedia/HTMLBook,oreillymedia/HTMLBook,wastemobile/HTMLBook,wastemobile/HTMLBook,gitenberg-dev/HTMLBook,mushroomgithub/HTMLBook,macmillanpublishers/HTMLBook